I. Field of the Invention
The present invention relates to a fuel delivery system and, more particularly, to a fuel delivery system for an internal combustion engine having fuel injectors.
II. Description of Related Art
Modern day internal combustion engines of the type used in automotive vehicles typically use fuel injectors in order to inject the fuel into the fuel combustion chamber. Many modern day internal combustion engines, furthermore, are direct injection engines in which the fuel injectors are open directly to the internal combustion chamber.
In order to overcome the high pressures present within the internal combustion chamber of a direct injection engine, the fuel must be delivered to the fuel injectors at a high fuel pressure. Conventionally, a high pressure pump provides fuel to a fuel rail which extends along the fuel injectors. Each injector is then fluidly connected to an internal fuel chamber of the fuel rail by a fuel port.
In order to achieve the high pressures necessary for the fuel injection of a direct injection engine, many previously known fuel pumps utilize a reciprocating piston within the pump chamber to not only induct fuel from the fuel source or gas tank into the pump chamber, but to also pump the fuel from the pump chamber out to the fuel rail. Typically, these pistons on these previously known fuel pumps utilize a cam lobe which is rotatably driven in synchronism with the engine such that the outer cam surface mechanically and reciprocally displaces the pump piston to pump the fuel.
While these previously known direct injection internal combustion engines enjoy high efficiency, fuel economy, and other advantages, one disadvantage of the direct injection engines is that pressure pulsations within the fuel delivery system create both vibration and noise from the engine. This noise is particularly audible at low engine speeds, such as idle.